In ancient times, the measurement accuracy of wooden scales could only be accurate to "money", which was far from satisfying the weighing of valuables. 1007, Song Dynasty official Liu devoted himself to developing the first weighing scale in China.
According to the measurement, the rod weighs one yuan (3. 1.25g), is one foot and two inches (400mm) long, and thallium weighs six cents (1.875g). The first deduction (initial milli), the minimum quantity is five cents (1.5625g), and the final quantity (maximum weighing) is one and a half yuan (4.69g); The second button (in the United States), and the last amount is one dollar (3.125g); The third button (the last one is ten cents), and the final amount is five cents (1.5625g).
This scale has a reasonable structure, and its measuring accuracy is one centimeter, which is equivalent to 3 1.25mg today. Such weighing accuracy is rare in the history of the development of weighing instruments in the world.
Extended data conversion between ancient silver coins and copper coins
The exchange ratio between ancient currencies, such as copper, silver and gold, changed as frequently as the current foreign exchange price, instead of 1 yuan being equal to 100. Generally speaking, it may be 1 two gold = 10 two silver = 10 penetration (hanging) copper coin = 10000 copper coin.
The reason why units such as "penetration" and "hanging" are mentioned here is because copper coins are the main currency in ancient circulation. In order to be easy to carry and count, copper coins are generally worn.
Different dynasties have different opinions. It is said that every 160 piece is strung in a string with hemp rope (60 pieces are put on both sides when wearing, and one piece is added to the bottom cover, which is actually 162 piece); There is also a saying that "a thousand words are consistent", which is more inclined according to the above conversion formula. That is to say, there is 1000 consistent (linked) money.